Form for molding monolithic baffle-walls for water-tube boilers and process of making the same



W. A. FORM FOR MOLDING MONOLITHIC BAFFLE WA MAKING HOFFMAN v LLS FOR WATER TUBE BOILERS AND PROCESS OF THE SA ENEWED OCT. 12 Pa 1 920. tented Mayw, 1921" 1ysizb7wzb7wAPPLlCA'l'iON FILED JAN.1

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WILLIAM: AUGUST HOFFMAN, OF ST. LOUIS, MISSOURI, ASSIGNOR TO JOHNS-MAN- VILLE INCQRPORATED, A CORPDRATION OF NEW YORK.

FORM F03 MOLDING MONOLITI-IIC IBAFFLE-VJALLS FOR tVATER-TUBE BOILERS AND PROCESS OF MAKING THE SAME.

Specification of Letters Eatent.

Patented May MD, 1921.

Application filed January 13, 1920, Serial No. 351,169. Renewed October 12, 1920. Serial No. 416,511.

To all to/tom it may concern:

Be it known that 1, WILLIAM AUGUST HOFFMAN, a citizen of the United States of America, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements in Forms for Molding Monolithic Bafi'le Walls for VV-ater Tube Boilers and Processes of Making the Same, of which the following is a specification.

My invention relates to water tube boilers in general and more specifically consists of a form for molding the monolithic battle walls now employed in many types of such boilers. As the tubes in such boilers are massed together in large numbers and located closely to -ether to save space, it is a somewhat (lith cult matter to get the necessary forms in and around the tubes so that the plastic mixture for forming such desired batlle walls can be poured into the forms and allowed to set around the tubes.

My invention supplies an inexpensive,

convenient apparatus and method for doing this and the best form of such apparatus at present known to me embodying the invention is illustrated in the accompanying sheet of drawings in which Figure 1 is a vertical, longitudinal section of a well known type of water tube boiler showing the location of the batlle walls;

Fig. 2, is a front view with parts broken away of one of the built-up partitions forming the molding for the battle wall constructed in accordance with my invention, the boiler tubes being shown in section,

Fig. 3, is a cross section on the line 33, of Fig. 2, and shows the two partitions or form walls and the plastic material for the bafile walls poured into said form.

Fig. 4, is a detail perspective view of one of the split washers used in my invention, and

Fig. 5, is a similar view of the notched stick used for inserting the split washers in place.

Throughout the drawings like reference figures indicate like parts.

1, represents the boiler generally, having the closely massed set of water tubes, 2. The furnace or combustion chamber for the boiler has the usual bridge walls 3, 3, so as to force the hot gases to pass between the tubes. The action of the bridge walls is further increased by the baflie walls 4:, 4, which are built upon and serve as extensions of them. As shown by the arrows in Fig. 1, these bailie valls cause the hot gasesto pass back and forth across all of the tubes so that even heating of them is assured.

The spaces between the tubes 2, are obviously too small to permit the convenient installation of separate bricks with which to build up the baiile walls. It is therefore becoming customary to mold these baffle walls i, a, in position. To do this, it is necessary to build a form in and around thetubes and this, of course, consists of two partitions arranged parallel one to another, leav ing a space between them, into which fireproof cement or other plastic material may be poured and then allowed to set around the tubes. Accordin to my invention these partitions are built up in the following manner:

A series of+strips of wood or other stifi material 6-6, of such thickness as is consistent with their being slipped in diagonally between the boiler tubes, are inserted between each two diagonal rows of tubes and crossed in position as shown in Fig. 2. The tubes 2, being usually staggered regularly as shown, one set of strips 6, 6, are inserted slanting to the right and another set 7, 7, are inserted slanting to the left and those abutting against one of the furnace side walls as 5, are beveled oil at the ends as shown in Fig. 2.

This forms a lattice work surrounding the boiler tubes, but obviously large open spaces are left between the tubes and the strips forming the lattice. To cover these open ings, I employ a plurality of spring Washers 8-8, of any suitable material which are split as shown in Fig. i, and which can be snapped over the boiler tubes, one washer on each tube, to cooperate with the lattice work and form a substantially imperforate partition as indicated in Fig. 2.

The preferred method of building up these partitions is to first insert the lattice strips of one inclination as 6, 6, and then to insert the split washers 8, 8, by placing them one at a time in the end of a split stick 10, which is inserted between the tubes and then turned so that the washer snaps over the particular tube for which it is intended, and then after all the tubes have been equipped with washupper and lower ends of the lattice strips may be nailed or otherwise firmly fastened to horizontal strips 9, 9, as clearly shown in Figs. 2 and 3. Two such partitions having been formed about the tubes at a proper distance apart, as shown in Fig. 3, the plastic material 11, is then poured in and allowed to set. This forms a monolithic baffle wall, as shown in Fig. 1. If desired, the lattice strips may then be unfastened one from another and withdrawn foruse again and the split washers may also be sprung off of the tubes if the operation of so salvaging them is not more costly than it would be to supply new ones for the next job. On the other hand, of course, the parts may all be left in position and burned off when the boiler furnace goes into operation.

Having described my invention, I claim:

1. A form for molding a monolithic baffle wall around a set of regularly spaced boiler tubes which comprises in combination a series of strips of stiff material inserted diagonally between the tubesand arranged all in substantially the same plane, a series of washers placed one around each tube adjacent to the strips, and a second series of strips inserted between the tubes at an inclination opposite to that of the first set, adjacent to and on the opposite side of the washers.

2. A structure such as set forth in claim 1 combined with horizontal top and bottom strips to which the ends of the diagonally arranged strips are fastened.

3. A form for molding a monolithic baffle wall around a set of staggered boiler tubes which comprises in combination two properly spaced partitions extending crosswise of the tubes, each partition being composed of a lattice work of narrow, stiff strips inserted between the tubes, and a washer around each tube adjacent each lattice of a diameter sufficient to cover the spaces left between the tubes and strips forming the lattice.

l. The method of building a monolithic baflle wall about and across a set of staggered boiler tubes which comprises the following steps: first inserting a series of stiff strips diagonally between the tubes, all the strips being in substantially the same plane; second, inserting a series of split washers and springing one around each tube adjacent to the set of strips; third, inserting a second set of strips on the other side of the washers oppositely inclined to those of the first set; fourth, building another similar form around the tubes at a distance from the first, and fifth, pouring a plastic mass of high temperature cement between the two sets of assembled strips and washers so installed, and allowing the same to set.

WILLIAM AUGUST HOFFMAN.

Witnesses:

N. L. NICHOLSON, FRED SURVIDGE. 

